SGM2028
500mA, Ultra Low Dropout,
Low Power, RF Linear Regulators
GENERAL DESCRIPTION
The SGM2028 is a low-power, low-noise, low-dropout,
CMOS linear voltage regulator that operates from a 2.5V
to 5.5V input voltage. It is the perfect choice for low
voltage, low power applications. A low ground current
makes this part attractive for battery operated power
systems. The SGM2028 also offers ultra low dropout
voltage to prolong battery life in portable electronics.
Systems requiring a quiet voltage source, such as RF
applications, will benefit from the SGM2028’s ultra low
output noise (30µV
RMS
) and high PSRR. An external
noise bypass capacitor connected to the device’s BP pin
can further reduce the noise level.
Other features include output current limit and thermal
shutdown protection.
FEATURES
500mA Guaranteed Output Current
Ultra Low Dropout Voltage
Low Output Noise
Thermal-Overload Protection
Output Current Limit
High PSRR (73dB at 1kHz)
SGM2028-2.8 and SGM2028-ADJ:
110kΩ Pull Down Resistor at EN Pin
SGM2028-3.3: No Pull Down Resistor at EN Pin
Available Fixed Output Voltages: 2.8V and 3.3V
Adjustable Output from 1.2V to 5.0V
-40℃ to +85℃ Operating Temperature Range
Available in Green SOT-23-5 Package
APPLICATIONS
The SGM2028 is available in Green SOT-23-5 package.
It operates over an ambient temperature range of -40°C
to +85°C.
Cellular Telephones
Cordless Telephones
PCMCIA Cards
Modems
MP3 Player
Hand-Held Instruments
Palmtop Computers
Electronic Planners
Portable/Battery-Powered Equipment
SG Micro Corp
www.sg-micro.com
REV. B. 1
SGM2028
PACKAGE/ORDERING INFORMATION
MODEL
SGM2028-3.3
SGM2028-2.8
SGM2028-ADJ
NOTE:
XX
= Date Code.
V
OUT
(V)
3.3V
2.8V
ADJ
PIN-
PACKAGE
SOT-23-5
SOT-23-5
SOT-23-5
500mA, Ultra Low Dropout,
Low Power, RF Linear Regulators
ORDERING
NUMBER
SGM2028-3.3YN5G/TR
SGM2028-2.8YN5G/TR
SGM2028-ADJYN5G/TR
PACKAGE
MARKING
S55XX
S58XX
S4BXX
PACKAGE
OPTION
Tape and Reel, 3000
Tape and Reel, 3000
Tape and Reel, 3000
MARKING INFORMATION
SYY X X
Date code - Month ("A" = Jan. "B" = Feb.
…
"L" = Dec.)
Date code - Year ("9" = 2009, "A" = 2010
…)
Chip I.D.
For example: S55AJ (2010, October)
ABSOLUTE MAXIMUM RATINGS
IN to GND................................................................. -0.3V to 6V
Output Short-Circuit Duration ...........................................Infinite
EN to GND................................................... -0.3V to (V
IN
+0.3V)
OUT, BP/FB to GND................................... -0.3V to (V
IN
+ 0.3V)
Power Dissipation, P
D
@ T
A
= 25℃
SOT-23-5.......................................................................... 0.34W
Package Thermal Resistance
SOT-23-5,
θ
JA
................................................................367℃/W
Operating Temperature Range............................-40℃ to +85℃
Junction Temperature........................................................ 150℃
Storage Temperature Range............................. -65℃ to +150℃
Lead Temperature (Soldering, 10s).................................. 260℃
ESD Susceptibility
HBM.................................................................................4000V
MM.....................................................................................400V
CAUTION
This integrated circuit can be damaged by ESD if you don’t pay
attention to ESD protection. SGMICRO recommends that all
integrated circuits be handled with appropriate precautions.
Failure to observe proper handling and installation procedures
can cause damage. ESD damage can range from subtle
performance degradation to complete device failure. Precision
integrated circuits may be more susceptible to damage because
very small parametric changes could cause the device not to
meet its published specifications.
SGMICRO reserves the right to make any change in circuit
design, specification or other related things if necessary without
notice at any time. Please contact SGMICRO sales office to get
the latest datasheet.
NOTE:
Stresses beyond those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. These
are stress ratings only, and functional operation of the device at
these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
SG Micro Corp
www.sg-micro.com
2
SGM2028
500mA, Ultra Low Dropout,
Low Power, RF Linear Regulators
PIN CONFIGURATION
(TOP VIEW)
IN
1
2
5
OUT
GND
EN
3
SOT-23-5
4
BP/FB
PIN DESCRIPTION
PIN
1
2
3
NAME
IN
GND
EN
BP
4
FB
5
OUT
FUNCTION
Regulator Input. Supply voltage can range from 2.5V to 5.5V. Bypass with a 1μF
capacitor to GND.
Ground.
Shutdown Input. A logic low reduces the supply current to 10nA. Connect to IN for
normal operation.
Reference-Noise Bypass (fixed voltage version only). Bypass with a low-leakage 0.01μF
ceramic capacitor for reduced noise at the output.
Feedback Pin (adjustable voltage version only). This is used to set the output voltage of
the device.
Regulator Output.
SG Micro Corp
www.sg-micro.com
3
SGM2028
500mA, Ultra Low Dropout,
Low Power, RF Linear Regulators
ELECTRICAL CHARACTERISTICS
(V
IN
= V
OUT (NOMINAL)
+ 0.5V or 2.5V, whichever is greater, Full = -40℃ to +85℃, unless otherwise noted. For SGM2028-ADJ, V
OUT
=
3.3V.)
PARAMETER
Input Voltage
Output Voltage Accuracy
Maximum Output Current
Current Limit
Ground Pin Current
(2)
(1)
SYMBOL
V
IN
I
OUT
= 0.1mA
CONDITIONS
TEMP
+25℃
+25℃
+25℃
MIN
2.5
-3
500
510
TYP
MAX
5.5
+3
UNITS
V
%
mA
mA
I
LIM
I
Q
No Load, V
EN
= 2V
I
OUT
= 100mA
+25℃
+25℃
115
54
220
90
270
420
0.095
0.0075
µA
Dropout Voltage
I
OUT
= 300mA
I
OUT
= 500mA
+25℃
162
270
mV
Line Regulation
Load Regulation
Output Voltage Noise
Power Supply Rejection Ratio
SHUTDOWN
EN Input Threshold
Shutdown Supply Current
Shutdown Exit Delay
Thermal Shutdown
Temperature
Thermal Shutdown
Hysteresis
(3)
ΔV
LNR
ΔV
LDR
e
n
PSRR
V
IN
= 2.5V to 5.5V, I
OUT
= 1mA
I
OUT
= 0.1mA to 500mA, C
OUT
= 1µF
f = 10Hz to 100kHz, C
BP
= 0.01µF,
C
OUT
= 10µF
C
BP
= 0.1μF, I
OUT
= 50mA,
C
OUT
= 1μF, V
IN
= V
OUT
+ 1V
f = 217Hz
f = 1kHz
+25℃
+25℃
+25℃
+25℃
+25℃
0.02
0.0025
30
77
73
%/V
%/mA
µV
RMS
dB
dB
V
IH
V
IL
I
Q(SHDN)
V
IN
= 2.5V to 5.5V
V
EN
= 0.3V
C
BP
= 0.01μF, C
OUT
=1μF, No Load
Full
Full
+25℃
+25℃
1.5
0.3
0.01
30
V
μA
μs
THERMAL PROTECTION
T
SHDN
ΔT
SHDN
150
15
℃
℃
NOTES:
1. Maximum output current is affected by PCB layout, size of metal trace, the thermal conduction path between metal layers and the
environment of the system.
2. The dropout voltage is defined as V
IN
- V
OUT
, when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
+ 0.5V.
(Only applicable for V
OUT
= +2.5V to +5.0V.)
3. Time needed for V
OUT
to reach 90% of final value.
SG Micro Corp
www.sg-micro.com
4
SGM2028
500mA, Ultra Low Dropout,
Low Power, RF Linear Regulators
TYPICAL APPLICATION CIRCUITS
INPUT
2.5V to 5.5V
IN
C
IN
1μF
OUT
C
OUT
1μF
ON
OFF
GND
R
2
GND
OUTPUT
INPUT
2.5V to 5.5V
C
IN
1μF
OUTPUT
IN
OUT
C
OUT
1μF
SGM
2028-ADJ
EN
FB
R
1
SGM2028
EN
BP
ON
OFF
C
BP
0.01μF
NOTE: Choose R
2
= 47kΩ to maintain a 26μA minimum load.
Calculate the value for R
1
using the following equation:
V
R
1
½
R
2
OUT
-1
1.206V
SG Micro Corp
www.sg-micro.com
5
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